Mechanisms of Intermediate Distance Space Perception

描述（由申请人提供）：中距离范围（2-25米）的视觉空间感知具有多方面的功能。它可以让观察者感知物体的三维形状、大小和位置，在空间中定位并指导我们的行动。然而，尽管它在使观察者能够在自然环境中互动方面很重要，但对中距离空间感知机制的了解尚不完整。该项目的长期目标是了解空间感知的基本机制，并发现这些机制如何调节人类的空间感知和行动。关于在地面上定位物体的能力，先前的研究发现，视觉系统通过构建地面表面的表示，然后将其作为参考框架来定位地面上的物体，从而实现这一目标。定位悬浮物需要确定悬浮物与地面参考系之间的相对位置。最近的实证研究为地面空间感知的概念提供了关键证据，并导致了地表表征的几个基本机制的发现。这一进展推动了一个更全面的理论框架的制定，以理解当前提案中视觉系统如何形成基于地面的感知空间。具体目标是寻求可量化的经验证据来充实和推进该框架。以下三个广泛定义的问题将被调查：a .由SSIP用来表示地面和其他表面的感知机制B.自上而下的处理在空间感知中的作用C.定位与地面没有直接表面接触的物体研究将采用心理物理学方法来测试人类观察者，主要是在真实的3D环境中。此外，为了补充在真实3D环境中进行的研究，拟议的项目将通过利用虚拟现实技术来研究虚拟环境中的空间感知。这种方法不仅对控制实验刺激有用，而且对如何提高虚拟场景的沉浸感质量也有帮助。总的来说，从拟议项目中获得的发现和见解将推动人类在中距离范围内的空间感知科学。它还将提高我们对视觉功能受损的人所面临的视觉问题的理解。公共卫生相关性：研究中距离的空间感知很重要，因为我们日常活动的很大一部分，如运动和导航，都是在这个距离范围内进行的。除了对感知科学的贡献外，该项目所获得的知识还可以为视觉缺陷患者（例如斜视和弱视）的空间感知和行动问题以及普通人在非最佳视觉环境中遇到的问题提供见解。在拟议的项目中使用虚拟现实技术的方法有可能被改编成帮助有空间感知缺陷的人的有用工具。

DESCRIPTION (provided by applicant): Visual space perception in the intermediate distance range (2-25 meters) serves a multi-faceted function. It allows the observer to perceive the 3D shapes, sizes and locations of objects, orient in space and guides our actions. Yet, despite its importance in enabling the observer to interact in the natural environment, knowledge of the mechanisms underlying space perception in the intermediate distance is incomplete. The long-term objectives of this project are to understand the basic mechanisms of space perception and to discover how these mechanisms mediate human space perception and action. Pertaining to the ability to locate an object on the ground, previous work found that the visual system achieves this by constructing a representation of the ground surface and then uses it as a reference frame to localize an object on the ground. To localize a suspended object requires determining the relative position between the suspended object and the ground reference frame. Recent empirical studies have provided critical evidence for the notion of a ground-based space perception, and led to the discovery of several fundamental mechanisms for representing the ground surface. This progress has motivated the formulation of a more comprehensive theoretical framework for understanding how the visual system forms the ground-based perceptual space in the current proposal. The specific aims are to seek quantifiable empirical proofs to substantiate and advance the framework. The following three broadly defined issues will be investigated: A. The Perceptual Mechanisms Used by the SSIP to Represent the Ground and Other Surfaces B. The Role of Top-Down Processing in Space Perception C. Locating an Object that Does Not Have a Direct Surface Contact with the Ground The research will employ the psychophysical method to test human observers, predominantly in the real 3D environment. In addition, to complement the research performed in the real 3D environment, the proposed project will investigate space perception in the virtual environment by capitalizing on the virtual reality technology. This approach is not only useful for controlling the experimental stimulation, but will also yield insights into how one can improve the immersive quality of virtual scenes. Overall, the findings and insights gained from the proposed project will advance the science of human space perception in the intermediate distance range. It will also improve our understanding of the visual problems confronted by people with compromised visual functions. PUBLIC HEALTH RELEVANCE: Research of space perception in the intermediate distance is important because a significant proportion of our daily activity, such as locomotion and navigating, are performed over this distance range. Besides its contribution to perceptual sciences, the knowledge gained from this project can provide insights into the space perception and action problems of patients with visual deficits (e.g., in strabismus and amblyopia), and the problems encountered by ordinary people in non-optimal visual environments. The approach of using the virtual reality technology in the proposed project has the potential of being adapted into a useful tool for aiding people with space perception deficits.